Proximity sensor devices (also commonly called touch sensor devices) are widely used in a variety of electronic systems. A proximity sensor device typically includes a sensing region, often demarked by a surface, in which input objects can be detected. Example input objects include fingers, styli, and the like. The proximity sensor device can utilize one or more sensors based on capacitive, resistive, inductive, optical, acoustic and/or other technology. Further, the proximity sensor device may determine the presence, location and/or motion of a single input object in the sensing region, or of multiple input objects simultaneously in the sensor region.
The proximity sensor device can be used to enable control of an associated electronic system. For example, proximity sensor devices are often used as input devices for larger computing systems, including: notebook computers and desktop computers. Proximity sensor devices are also often used in smaller systems, including: handheld systems such as personal digital assistants (PDAs), remote controls, and communication systems such as wireless telephones and text messaging systems. Increasingly, proximity sensor devices are used in media systems, such as CD, DVD, MP3, video or other media recorders or players. The proximity sensor device can be integral or peripheral to the computing system with which it interacts.
In the past, some proximity sensors have been implemented with additional ability to detect and determine force applied to a surface of the sensor. For example, by making an estimation of applied force by measuring the increased capacitance that is the result of the increased contact area when a finger is pressed against the surface. Unfortunately, some implementations of these proximity sensors have had limited accuracy when estimating applied force using these techniques. Because of questionable accuracy, such sensors have typically had limited ability to use such determined force as a basis for determining user input. This limits the flexibility of the proximity sensor device to function as an input device. Thus, there exists a need for improvements in proximity sensor device, and in particular, the ability of proximity sensor devices to determine and respond to indications of applied force.
Furthermore, it is desirable in some applications to provide feedback to users of proximity sensor devices. Specifically, it is desirable in many devices to provide force and motion at the surface of the device where it may be felt by the user. This is commonly referred to as “haptic” feedback. Haptic feedback may be used to let a user know when certain actions are occurring or about to occur on a device. Thus, there exists a continuing need for improvements in proximity sensor device, and in particular, the ability of proximity sensor devices to provide haptic feedback to users of such devices.
Other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.